lily/rest-collision.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2010 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "rest-collision.hh"
  21
  22 #include <cmath>                // ceil.
  23 using namespace std;
  24
  25 #include "directional-element-interface.hh"
  26 #include "duration.hh"
  27 #include "international.hh"
  28 #include "item.hh"
  29 #include "note-column.hh"
  30 #include "output-def.hh"
  31 #include "pointer-group-interface.hh"
  32 #include "rest.hh"
  33 #include "rhythmic-head.hh"
  34 #include "staff-symbol-referencer.hh"
  35 #include "stem.hh"
  36 #include "grob.hh"
  37 #include "warn.hh"
  38
  39 MAKE_SCHEME_CALLBACK (Rest_collision, force_shift_callback, 1);
  40 SCM
  41 Rest_collision::force_shift_callback (SCM smob)
  42 {
  43   Grob *them = unsmob_grob (smob);
  44   if (Note_column::has_rests (them))
  45     {
  46       Grob *collision = unsmob_grob (them->get_object ("rest-collision"));
  47
  48       if (collision)
  49         {
  50           (void) collision->get_property ("positioning-done");
  51         }
  52     }
  53   return scm_from_double (0.0);
  54 }
  55
  56 MAKE_SCHEME_CALLBACK_WITH_OPTARGS (Rest_collision, force_shift_callback_rest, 2, 1, "");
  57 SCM
  58 Rest_collision::force_shift_callback_rest (SCM rest, SCM offset)
  59 {
  60   Grob *rest_grob = unsmob_grob (rest);
  61   Grob *parent = rest_grob->get_parent (X_AXIS);
  62
  63   /*
  64     translate REST; we need the result of this translation later on,
  65     while the offset probably still is 0/calculation-in-progress.
  66    */
  67   if (scm_is_number (offset))
  68     rest_grob->translate_axis (scm_to_double (offset), Y_AXIS);
  69
  70   if (Note_column::has_interface (parent))
  71     force_shift_callback (parent->self_scm ());
  72
  73   return scm_from_double (0.0);
  74 }
  75
  76 void
  77 Rest_collision::add_column (Grob *me, Grob *p)
  78 {
  79   Pointer_group_interface::add_grob (me, ly_symbol2scm ("elements"), p);
  80
  81   /*
  82     only add callback for the rests, since we don't move anything
  83     else.
  84
  85     (not?)
  86   */
  87   add_offset_callback (p, Rest_collision::force_shift_callback_proc, Y_AXIS);
  88   p->set_object ("rest-collision", me->self_scm ());
  89
  90   Grob *rest = unsmob_grob (p->get_object ("rest"));
  91   if (rest)
  92     {
  93       chain_offset_callback (rest,
  94                              Rest_collision::force_shift_callback_rest_proc, Y_AXIS);
  95     }
  96 }
  97
  98 /*
  99   TODO: look at horizontal-shift to determine ordering between rests
 100   for more than two voices.
 101 */
 102 MAKE_SCHEME_CALLBACK (Rest_collision, calc_positioning_done, 1);
 103 SCM
 104 Rest_collision::calc_positioning_done (SCM smob)
 105 {
 106   Grob *me = unsmob_grob (smob);
 107
 108   me->set_property ("positioning-done", SCM_BOOL_T);
 109
 110   extract_grob_set (me, "elements", elts);
 111
 112   vector<Grob*> rests;
 113   vector<Grob*> notes;
 114
 115   for (vsize i = 0; i < elts.size (); i++)
 116     {
 117       Grob *e = elts[i];
 118       if (unsmob_grob (e->get_object ("rest")))
 119         rests.push_back (e);
 120       else
 121         notes.push_back (e);
 122     }
 123
 124   /*
 125     handle rest-rest and rest-note collisions
 126
 127     [todo]
 128     * decide not to print rest if too crowded?
 129     */
 130
 131   /*
 132     no partners to collide with
 133   */
 134   if (rests.size () + notes.size () < 2)
 135     return SCM_BOOL_T;
 136
 137   Real staff_space = Staff_symbol_referencer::staff_space (me);
 138   /*
 139     only rests
 140   */
 141   if (!notes.size ())
 142     {
 143
 144       /*
 145         This is incomplete: in case of an uneven number of rests, the
 146         center one should be centered on the staff.
 147       */
 148       Drul_array<vector<Grob*> > ordered_rests;
 149       for (vsize i = 0; i < rests.size (); i++)
 150         {
 151           Grob *r = Note_column::get_rest (rests[i]);
 152
 153           Direction d = get_grob_direction (r);
 154           if (d)
 155             ordered_rests[d].push_back (rests[i]);
 156           else
 157             rests[d]->warning (_ ("cannot resolve rest collision: rest direction not set"));
 158         }
 159
 160       Direction d = LEFT;
 161       do
 162         vector_sort (ordered_rests[d], Note_column::shift_less);
 163       while (flip (&d) != LEFT)
 164         ;
 165
 166       do
 167         {
 168           if (ordered_rests[d].size () < 1)
 169             {
 170               if (ordered_rests[-d].size () > 1)
 171                 ordered_rests[-d][0]->warning (_ ("too many colliding rests"));
 172
 173               return SCM_BOOL_T;
 174             }
 175         }
 176       while (flip (&d) != LEFT);
 177
 178       Grob *common = common_refpoint_of_array (ordered_rests[DOWN], me, Y_AXIS);
 179       common = common_refpoint_of_array (ordered_rests[UP], common, Y_AXIS);
 180
 181       Real diff
 182         = (ordered_rests[DOWN].back ()->extent (common, Y_AXIS)[UP]
 183            - ordered_rests[UP].back ()->extent (common, Y_AXIS)[DOWN]) / staff_space;
 184
 185       if (diff > 0)
 186         {
 187           int amount_down = (int) ceil (diff / 2);
 188           diff -= amount_down;
 189           Note_column::translate_rests (ordered_rests[DOWN].back (),
 190                                         -2 * amount_down);
 191           if (diff > 0)
 192             Note_column::translate_rests (ordered_rests[UP].back (),
 193                                           2 * int (ceil (diff)));
 194         }
 195
 196       do
 197         {
 198           for (vsize i = ordered_rests[d].size () -1; i-- > 0;)
 199             {
 200               Real last_y = ordered_rests[d][i + 1]->extent (common, Y_AXIS)[d];
 201               Real y = ordered_rests[d][i]->extent (common, Y_AXIS)[-d];
 202
 203               Real diff = d * ((last_y - y) / staff_space);
 204               if (diff > 0)
 205                 Note_column::translate_rests (ordered_rests[d][i], d * (int) ceil (diff) * 2);
 206             }
 207         }
 208       while (flip (&d) != LEFT);
 209     }
 210   else
 211     {
 212       /*
 213         Rests and notes.
 214       */
 215       if (rests.size () > 1)
 216         warning (_ ("too many colliding rests"));
 217       Grob *rcol = 0;
 218       Direction dir = CENTER;
 219
 220       for (vsize i = rests.size (); !rcol && i--;)
 221         if (Note_column::dir (rests[i]))
 222           {
 223             rcol = rests[i];
 224             dir = Note_column::dir (rcol);
 225           }
 226
 227       if (!rcol)
 228         return SCM_BOOL_T;
 229
 230       Grob *rest = Note_column::get_rest (rcol);
 231       Grob *common = common_refpoint_of_array (notes, rcol, Y_AXIS);
 232
 233       Interval restdim = rcol->extent (common, Y_AXIS);
 234       if (restdim.is_empty ())
 235         return SCM_BOOL_T;
 236
 237       Real staff_space = Staff_symbol_referencer::staff_space (rcol);
 238       Real minimum_dist = robust_scm2double (me->get_property ("minimum-distance"), 1.0) * staff_space;
 239
 240       Interval notedim;
 241       for (vsize i = 0; i < notes.size (); i++)
 242         {
 243           if (Note_column::dir (notes[i]) == -dir
 244               // If the note has already happened (but it has a long duration, so there is a collision),
 245               // don't look at the stem. If we do, the rest gets shifted down a lot and it looks bad.
 246               || dynamic_cast<Item*> (notes[i])->get_column () != dynamic_cast<Item*> (rest)->get_column ())
 247             {
 248               /* try not to look at the stem, as looking at a beamed
 249                  note may trigger beam positioning prematurely.
 250
 251                  This happens with dotted rests, which need Y
 252                  positioning to compute X-positioning.
 253               */
 254               Grob *head = Note_column::first_head (notes[i]);
 255               if (head)
 256                 notedim.unite (head->extent (common, Y_AXIS));
 257               else
 258                 programming_error ("Note_column without first_head()");
 259             }
 260           else
 261             notedim.unite (notes[i]->extent (common, Y_AXIS));
 262         }
 263
 264       Real y = dir * max (0.0,
 265                           -dir * restdim[-dir] + dir * notedim[dir]  + minimum_dist);
 266
 267       int stafflines = Staff_symbol_referencer::line_count (me);
 268       if (!stafflines)
 269         {
 270           programming_error ("no staff line count");
 271           stafflines = 5;
 272         }
 273
 274       // move discretely by half spaces.
 275       int discrete_y = dir * int (ceil (y / (0.5 * dir * staff_space)));
 276
 277       // move by whole spaces inside the staff.
 278       if (fabs (Staff_symbol_referencer::get_position (rest)
 279                 + discrete_y) < stafflines + 1)
 280         {
 281           discrete_y = dir * int (ceil (dir * discrete_y / 2.0) * 2.0);
 282         }
 283
 284       Note_column::translate_rests (rcol, discrete_y);
 285     }
 286   return SCM_BOOL_T;
 287 }
 288
 289 ADD_INTERFACE (Rest_collision,
 290                "Move around ordinary rests (not multi-measure-rests) to avoid"
 291                " conflicts.",
 292
 293                /* properties */
 294                "minimum-distance "
 295                "positioning-done "
 296                "elements "
 297                );
 298